Screw anchored wallboard assembly

ABSTRACT

The embodiment of the invention disclosed herein is directed to a screw assembly comprising a cylindrical shank having a thread formed therealong and a conical head formed at the trailing end of the shank with slot means formed in the head for receiving a driving tool. An annular flange is formed at the top of the conical head and cooperates with a conical washer to form an annular groove or undercut between the flange and paper surface of wallboard when the screw is driven home firmly to hold the wallboard to support studs or the like. When the screw assembly is fully driven home, it forms an outwardly diverging depression about the screw head with the top surface of the screw head beneath the surface of the wallboard. A quantity of topping compound is applied over the screw head into the diverging depression completely to cover the screw head from view. The annular groove formed by the flange and the conical washer allows a quantity of the topping compound to flow therein thus providing a more secure bond of the topping compound patch so that flaking and chipping will not occur.

llnited States Patent Reiland Dec. 24, 1974 SCREW ANCHORED WALLBOARDASSEMBLY [75] Inventor: Bernard F. Reiland, Rockford, Ill.

[73] Assignee: Textron, Inc., Providence, R.I.

[22] Filed: Jan. 15, 1973 [21] Appl. No.: 323,879

[52] US. Cl 52/363, 52/715, 85/41,

85/50 [51] Int. Cl..... E04b 2/58, F16b 25/00, F16b 39/26 [58] Field ofSearch 52/418, 210, 213, 214,

[56] References Cited UNITED STATES PATENTS 156,699 11/1874 Fuller 85/50R 1,564,455 12/1925 Stanbro 52/362 1,672,099 6/1928 Schumacher 52/3612,157,374 5/1939 Wells 52/363 3,298,270 l/1967 Launay 85/50 R 3,322,0195/1967 Lovisek 52/363 3,556,570 l/l971 Cosenza 85/50 R FOREIGN PATENTSOR APPLICATIONS 1,322,847 2/1963 France 85/50 R 1,068,245 5/1967 GreatBritain 85/41 Primary Examiner-Henry C. Sutherland Attorney, Agent, orFirm-Ols0n, Trexler, Wolters, Bushnell & Fosse, Ltd.

[ ABSTRACT The embodiment of the invention disclosed herein is directedto a screw assembly comprising a cylindrical shank having a threadformed therealong and a conical head formed at the trailing end of theshank with slot means formed in the head for receiving a driving tool.An annular flange is formed at the top of the conical head andcooperates with a conical washer to form an annular groove or undercutbetween the flange and paper surface of wallboard when the screw isdriven home firmly to hold the wallboard to support studs or the like.When the screw assembly is fully driven home, it forms an outwardlydiverging depression about the screw head with the top surface of thescrew head beneath the surface of the wallboard. A quantity of toppingcompound is applied over the screw head into the diverging depressioncompletely to cover the screw head from view. The annular groove formedby the flange and the conical washer allows a quantity of the toppingcompound to flow therein thus providing a more secure bond of thetopping compound patch so that flaking and chipping will not occur.

3 Claims, 3 Drawing Figures lllllllll' SCREW ANCHORED WALLBOARD ASSEMBLYBACKGROUND OF THE INVENTION This invention relates generally tofasteners, and more particularly to fasteners of the type used to securewallboard such as drywall to supporting studs.

The present invention contemplates the method of forming a wallstructure wherein plasterboard is secured to upstanding wood or metalstuds. Heretofore plasterboard has been traditionally nailed in placewhen positioned over wooden support studs. The nail heads are recessed aslight distance beneath the surface of the wallboard as a result of anover extended hammer blow which sets the nail slightly beneath thesurface. A quantity of plaster patch or plaster-like material commonlyreferred to as topping compound is applied over the nail head to fillthe depression so that a smooth wall surface is the visual result.However, with the increase use of metal support studs nailing in thisfashion is not advisable. To firmly secure wallboard to such metal studsa power driven threaded screw is commonly used and driven home by apnuematic or electric drill which has a slip clutch mechanism set at apredetermined torque condition. When the screw is inserted through thewallboard and threaded into the metal stud it is driven home to acondition where the top surface of the screw is recessed beneath thesurface of the wallboard. This condition causes an outwardly divergingdepression to occur around the screw head similar to the depressionformed by the over extended hammer blow, and this depression is filledin with the topping compound as mentioned above.

However, problems have occurred in the use of such threaded power drivenscrews in that the twisting action of the screw head just as it isdriven home against the paper surface of the wallboard tends to twistand tear the paper surface. This condition produces an undesirableappearance and weakens the ultimate connection therebetween. Also, as aresult of vibration, thermal expansion, and other phenomenon the plasterpatch over the screw head sometimes flakes or chips away because of poorgripping action of the plaster patch over the screw head.

SUMMARY OF THE INVENTION Accordingly, it is an object of this inventionto provide a new and improved screw assembly for use in forming drywallstructures which screw assembly will not twist or tear the paper surfaceof the drywall when driven home and which will provide improved grippingaction of the plaster patch formed over the head of the screw.

Another object of this invention is to provide an improved screwassembly which is efficient and reliable in use but which is simple andinexpensive to manufacture.

Many other objects, features and advantages of this invention will bemore fully realized and understood from the following detaileddescription when taken in conjunction with the accompanying drawingswherein like reference numerals throughout the various views of thedrawings are intended to designate similar elements and components.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary view showing awall structure constructed in accordance with the principles of thisinvention;

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, andshowing the details of the screw assembly of this invention; and

FIG. 3 is a surface view of the wall structure showing a plaster patchcovering the recessed head portion of the screw of FIG. 2.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring now to FIG.1, there is seen a wall structure constructed in accordance with theprinciples of this invention and designated generally by referencenumeral 10. The wall structure 10 is formed of a plurality of wallboardpanels 12 which preferably are of plasterboard, or the like, and held inposition by a plurality of screws 14 which pass through the wallboardpanel and are threadedly inserted into vertical support studs 16. Herethe support studs are metal but it will be understood that the screwassemblies of this invention may be incorporated in wood wall studs ifdesired. The wall structure 10 may be of any configuration and mayinclude a door frame unit 17 as well as windows or the like, not shown.

The screw assembly 14 is best illustrated in FIG. 2. Here the screwassembly comprises a shank portion 20 having threads 21 formedtherealong and a conical head 22 formed integral with the trailing end21a of the shank 20. The conical surface 24 is directed toward thesurface of the wallboard 12 while a flat top portion 26 of the head 22is arranged so as to be beneath the surface of the wallboard when thescrew 14 is driven fully home by an impact wrench, or the like, insertedinto a tool receiving slot 28.

Most advantageously, an annular flange 30 is formed at the endmostportion of the conical head and cooperates with a conical washer 32 in aunique and novel manner. While the illustrated embodiment hereindiscloses an annular flange and conical washer, it will be understoodthat other topping compound gripping means may be incorporated about theperiphery of the head 22 to cause plaster-like material to flow betweenthe head and the paper surface of the wallboard. When the washer 32 isincorporated, it is provided with an aperture 34 centrally thereof andhas axially extended portions 36 circumscribing the shank 20.

Preferably, the washer 32 is placed on the shank 20 before the threads21 are formed thereon. The apertue 34 is therefore selected so as to besufficiently large to fit easily over the shank 20 but of a size to besmaller than the major diameter of the threads after they are formed bya thread rolling process. By so forming the aperture smaller than themajor diameter of the thread 21 the conical washer 32 is at all timespositioned on the screw and therefore forms the screw assembly 14.

In accordance with this invention the washer 32 has a radial extentwhich is inwardly of the flange 30 to form a recess 38 which cooperateswith the paper surface of the wallboard 12 to form an annular groove orundercut 40. The topping compound or plaster patch material which isused will flow into the annular groove 40 for a more secure bond.

When the screw assembly 14 is fully driven home it forms an outwardlydiverging depression 42 about the screw head and causes linear stretchmarks to form in the paper surface of the wallboard 12. These linearstretch marks are illustrated in FIG. 3. Therefore, by utilizing aconical washer to act as a bearing surface between the rotating actionof the conical head of the screw and the paper surface of the wallboard,twisting and tearing of the paper does not occur.

The method of this invention is carried out by first placing wallboardover the studs in a predetermined orientation, they being either set inposition vertically or horizontally, and then inserting a plurality ofscrew assemblies 14 through the wallboard and into the support stud forholding the wallboard in place. The screw assemblies are driven home toform the outwardly diverging depression 42 about the head portion. Themethod is further accomplished by placing a quantity of topping compound44 in the outwardly diverging depression for covering the screw head andfor allowing the topping compound 44 to flow into the annular groove 40formed between the paper of the wallboard and the annular flange 30.

While a single specific embodiment of the screw assembly of thisinvention is illustrated it will be understood that modifications andvariations may be effected without departing from the spirit and scopeof the novel concepts disclosed and claimed herein.

The invention is claimed as follows:

1. In combination with a wall structure comprising a plurality ofsupporting studs over which sheets of wall board are secured; a screwassembly penetrating said wall board and holding the same to said studs,said screw assembly comprising a cylindrical shank having threaded meansformed therealong for threading the screw assembly through a wall boardpanel and into engagement with one of said support studs, saidcylindrical shank having a leading end inserted into the support studand a trailing end spaced from said support stud, a conical head formedintegral with said trailing end of said shank, a radially extendingannular flange formed about said conical head, a washer carried on saidshank and having a conical portion complementally engaged with saidconical head and an aperture formed centrally therein to receiving saidcylindrical shank, said conical washer portion having a wall thickness,a radial extent and an axial length such that the outer conical surfaceof said conical portion engages the adjacent wall board surface formingan outwardly diverging depression therein and the maximum diameter edgeof said washer is spaced inwardly of the peripheral edge of said flangeand inwardly of the adjacent wall board surface in the depression tocooperate with said radially extending flange to form an annular recessimmediately adjacent said flange on the underside thereof, with the topsurface of said conical head being disposed beneath the normal outersurface of said wall board and with the peripheral edge of said flangespaced inwardly of the adjacent wall board surface in the depression toprovide access opening to said recess, and a topping compound patchfilling said depression and covering said screw, said topping compoundbeing flowed through said access opening into said annular recess andhardened to provide gripping anchorage means for maintaining said patchin place.

2. The wall structure according to claim 1, wherein said conical washerhas an axially directed portion about said aperture.

3. The wall structure according to claim 2, wherein the diameter of saidaperture is less than the major diameter of the threaded portion of saidshank thereby preventing said conical washer from being removed fromsaid shank.

1. In combination with a wall structure comprising a plurality ofsupporting studs over which sheets of wall board are secured; a screwassembly penetrating said wall board and holding the same to said studs,said screw assembly comprising a cylindrical shank having threaded meansformed therealong for threading the screw assembly through a wall boardpanel and into engagement with one of said support studs, saidcylindrical shank having a leading end inserted into the support studand a trailing end spaced from said support stud, a conical head formedintegral with said trailing end of said shank, a radially extendingannular flange formed about said conical head, a washer carried on saidshank and having a conical portion complementally engaged with saidconical head and an aperture formed centrally therein to receiving saidcylindrical shank, said conical washer portion having a wall thickness,a radial extent and an axial length such that the outer conical surfaceof said conical portion engages the adjacent wall board surface formingan outwardly diverging depression therein and the maximum diameter edgeof said washer is spaced inwardly of the peripheral edge of said flangeand inwardly of the adjacent wall board surface in the depression tocooperate with said radially extending flange to form an annular recessimmediately adjacent said flange on the underside thereof, with the topsurface of said conical head being disposed beneath the normal outersurface of said wall board and with the peripheral edge of said flangespaced inwardly of the adjacent wall board surface in the depression toprovide access opening to said recess, and a topping compound patchfilling said depression and covering said screw, said topping compoundbeing flowed through said access opening into said annular recess andhardened to provide gripping anchorage means for maintaining said patchin place.
 2. The wall structure according to claim 1, wherein saidconical washer has an axially directed portion about said aperture. 3.The wall structure according to claim 2, wherein the diameter of saidaperture is less than the major diameter of the threaded portion of saidshank thereby preventing said conical washer from being removed fromsaid shank.